Have you ever thought about how that smooth and creamy bite of ice cream is the work of many engineers? Ice cream doesn’t have many ingredients—milk fat, milk solids, sugar, and sometimes stabilizers and emulsifiers— but it has many engineers that work on its production. The engineers involved in making the batches of ice cream include mechanical engineers, chemical engineers, computer engineers, electrical engineers, and environmental engineers. Engineers make factory ice cream smooth, creamy, cold, healthy and safe for us to eat.
Everyone likes their ice cream smooth and creamy and engineers play an important role in this. They make sure that the ice cream has just the right amount of solid, liquid and gas. Milk fat is important in making ice cream creamy and this milk comes to the factory from the dairy farms in refrigerated trucks. Chemical and mechanical engineers are involved in homogenization, which makes the ice cream smooth. Homogenization is a process that breaks the fat globules in the liquid mixture in to smaller pieces. This happens when the liquid is pushed through tiny tubes and the pressure breaks the globules apart.
Mixing also makes the ice cream smooth. Mechanical engineers design dashers or paddles to mix the ice cream in a special way that scrapes the ice crystals off the sides of the vat, so that the crystals are broken up and the ice cream stays smooth and creamy. The mixing also adds air to the ice cream mixture and the air bubbles attach to the fat globules. If it weren’t for the mixing, ice cream would just be ice. Chemical engineers make stabilizers and emulsifiers, which are used in some ice cream to make it smooth instead of icy. Ice cream wouldn’t be ice cream if it weren’t cold. Tubes with ammonia running through them keep the ice cream cold while the air is mixed in. The electrical engineers decide how much power is needed to run the refrigeration system. Also computer engineers design the computers that control the temperature of the freezer, the dashers’ mixing speed, measuring ingredients, and pasteurization.
It is important that ice cream is safe and healthy for people and the Earth. At the beginning of the process, pasteurization heats up the liquid mixture and kills the organisms that might cause disease. Another way to keep the ice cream factory free from disease is to clean up every night. Mechanical engineers design all of these cleaning machines. Environmental engineers are in charge of making sure the ice cream factory doesn’t pollute, so they design a waste water system to try to reuse the water after making ice cream.
Finally, the ice cream is packaged and loaded in to trucks to deliver to stores and markets. Maybe the next time you go to the store to buy ice cream you won’t just think about whether you want cookies and cream or rocky road, but you will think about the engineering involved in making this delicious treat.
- Ice Cream Treats: the Inside Scoop, by Paul Fleisher, Carolrhoda Books, Inc., 2001.
- The science of the scoop: Wheat proteins for ice cream?,by Kathy Wren, http://www.aaas.org/news/releases/2002/icecream.shtml
- Finding Science in Ice Cream-An Experiment for Secondary School Classrooms, by Dr. Douglass Goff, http://www.foodsci.uoguelph.ca/dairyedu/findsci.html
- Ice Cream Science, by Steve Mirsky, http://www.scientificamerican.com/podcast/episode.cfm?id=000B969C-1187-14AA-8EB283414B7FFE87
- Screaming for Ice Cream, by Emily Sohn, http://www.sciencenewsforkids.org/2005/07/screaming-forice-cream-2/